IBus could allow local users to capture key strokes of other locally logged in users.
USN-4134-1 fixed a vulnerability in IBus. The update caused a regression in some Qt applications and the fix was subsequently reverted in USN-4134-2. The regression has since been resolved and so this update fixes the original vulnerability.
24 March 2020
A security issue affects these releases of Ubuntu and its derivatives:
IBus could allow local users to capture key strokes of other locally logged in users.
USN-4134-1 fixed a vulnerability in IBus. The update caused a regression in some Qt applications and the fix was subsequently reverted in USN-4134-2. The regression has since been resolved and so this update fixes the original vulnerability.
We apologize for the inconvenience.
Original advisory details:
Simon McVittie discovered that IBus did not enforce appropriate access controls on its private D-Bus socket. A local unprivileged user who discovers the IBus socket address of another user could exploit this to capture the key strokes of the other user.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to reboot your computer to make all the necessary changes.